Such a valve has become known from West German Patent No. DE-PS 932,764.
In this prior-art pressure regulator, a bellows-shaped reference pressure chamber is filled under a defined pressure that adds, together with a compression spring, to an overall opening pressure for the closing element. This reference chamber is located above the valve closing body. The reference pressure chamber communicates with the ambient atmosphere, so that pressure variations in the ambient atmosphere have such an effect that the pressure exerted on the closing element increases as the atmospheric pressure increases and decreases as the atmospheric pressure decreases. Thus, the valve operates in such a way that the ambient pressure is taken into account. In various possible applications, especially aeronautics and space travel, the gas-carrying lines and especially the pressure-regulating and control devices are subject to great temperature variations. Since the modulus of elasticity of the elastic element also changes with changing ambient temperature, accurate pressure regulation, which requires constancy of the spring force, is only possible at increased expense. It may be assumed that the modulus of elasticity is known to change by ca. 0.0489% per .degree.C. based on a compression spring made of spring steel (X12 chrome-nickel 177) as an elastic element. This means that a standard deviation of ca. 3.4% can be expected in the case of a typical temperature change of 70.degree. C. If this deviation is to be avoided, it would be possible to use a special spring steel with a modulus of elasticity that remains constant in broad temperature ranges, but this would lead to an expensive embodiment. It was also suggested that a piston, which is connected to a reservoir for a liquid, e.g., silicone, be allowed to act on the spring in order to achieve temperature compensation of the spring force of a pressure regulator. When the spring force decreases as a consequence of increased temperature, the liquid expands and displaces the piston and consequently also the spring in such a direction that the controlling force of the spring will increase correspondingly. When the ambient temperature again decreases, the liquid reservoir shrinks, and the increasing spring force provides for a constant pressure effect (EP-A-113,470). This prior-art device has the disadvantage that an expensive design is needed in order to be able to allow the piston-cylinder arrangement to act only on the spring; in addition, expensive sealing measures are required to separate the gas chamber from the liquid reservoir. The need to constantly keep ready a substantial amount of liquid makes the prior-art pressure regulator unsuitable for use in the area of aeronautics and space travel because of the large weight. In addition, only liquids that do not freeze in the temperature range to be taken into account would be able to be selected.